Escapement mechanism



Dec. 10, 1968 5. N. w||.| |s ETAL ESCAPEMENT MECHANISM Filed Sept. 2. 1966 United States Patent 3,415,162 ESCAPEMENT MECHANISM Grant N. Willis, Bristol, and Irving Y. Lake, Terryville, Conn., assiguors to Arthur G. Russell Company, Incorporated, Bristol, Conn., a corporation of Connecticut Filed Sept. 2, 1966, Ser. No. 577,059 5 Claims. (Cl. 91-189) ABSTRACT OF THE DISCLOSURE Mechanism comprising a pair of operating rods reciprocable within a pair of passageways formed in a housing, and fluid operating means for controlling reciprocation of the operating rods, the fluid operating means including internal fluid passages connecting a forward portion of each one of the passageways with a rear portion of the other of the passageways only when both operating rods are in extended positions.

This invention generally relates to article handling mechanisms and particularly concerns escapement mechanisms for successively releasing a series of objects in a continuous operation.

A principal object of the invention is to provide an improved escapement mechanism of the reciprocating type for successively releasing a series of objects one at a time, as well as for releasing several objects at a time, in a controlled manner and at high delivery rates.

Another object of the invention is to provide an improved fluid operated escapement mechanism which is easily installed as an accessory in both new and existing equipment and which is particularly suited for feeding and counting applications.

A further object of the invention is to provide an escapement mechanism of the above described type incorporating a minimum number of parts essentially free of maintenance requirements.

Still another object of the invention is to provide an improved escapement mechanism which is both durable and dependable in operation for extended use over a long service life and which is provided in a rugged, compact assembly.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth, and the scope of the application of which will be indicated in the appended claims.

In the drawing:

FIG. 1 is an elevational view, partly in section and partly broken away, showing a preferred embodiment of the invention; and

FIG. 2 is a section view, partly broken away, taken generally along line 2-2 of FIG. 1.

Referring now to the drawing in detail, an escapement mechanism is illustrated having a rectangular housing 12 and a pair of axially movable operating rods 14, 16 projecting outwardly from a forward end 18 of the housing 12. It will be understood that the housing 12 may be mounted on a supporting structure, not shown, and the rods 14, 16 are alternately axially reciprocated for feeding or releasing a series of objects one at a time, e.g., in accordance with the demands of an associated machine. The escapement mechanism 10 can also be used to release several parts at a time, as in counting applications.

In the'preferred embodiment, the housing 12 is shown as being a solid body having forward portion 20 and rear portion or cylinder block 22 maintained in assembled re- Patented Dec. 10, 1968 lation by an overlying cover plate 24 secured by screws 26, and a pair of longitudinally extending passageways 28 are provided in the housing 12 receiving the rods 14, 16 for sliding movement. The outwardly projecting portions of the rods 14, 16 preferably are provided with threaded holes 29 for mounting suitable escapement fingers, not shown conforming to the objects which are to be handled.

The rear portions of the passageways 28 are of enlarged size to provide a pair of operating cylinders 30, 32 longitudinally extending side-by-side through the cylinder block 22, and actuating pistons 34, 36 on the rear ends of the rods 14, 16 are received in the cylinders 30, 32 for longtudinal reciprocating movement. Sleeves 38, 40 are secured in the forward ends of the cylinders 30, 32 forming seats for the pistons 34, 36 which divide their respective cylinders 30, 32 into forward and rear chambers.

A tight fluid seal is provided between the forward and rear chambers of the cylinders 30, 32 by annular seals 46, 48 retained in grooves 50, 52 extending around pistons 34, 36, and the forward chamber of cylinder 32 is sealed against fluid leakage past the sleeve 40 by an annular seal 54 securely seated in cylinder 32 (FIG. 2) to encircle the rod of piston 36. An O-ring 56 seated in sleeve 40 acts as a cushion for piston 36. A similar arrangement is provided for sealing the forward chamber of cylinder 30 and for cushioning piston 34.

An end member 58 of the housing 12 is fixed as by screw 60 to the rear end of the cylinder block 22. A pair of threaded ports 62, 64 are formed in the end member 58 which serve to connect the rear chambers of each operating cylinder 30, 32 with a pair of conventional hose connectors, not shown, whereby the cylinders 30, 32 are both adapted to be connected to a source of fluid under pressure, preferably compressed air. A gasket 66 is interposed between the end member 58 and the cylinder block 22 to provide a tight fluid seal at the rear ends of the cylinders, and the gasket 66 in conjunction with end member 58 of the housing 12 establishes seats for the pistons 34, 36 in their retracted positions.

It will be understood that a conventional multiway reversing valve is provided in the fluid circuit upstream of the ports 62, 64 for alternately supplying compressed air to each one of the cylinders 30, 32 and for successively venting the rear chamber of the other cylinder in turn. Timing of the valving operation may be obtained by a conventional cycle control device automatically operated in a well-known manner from the above-mentioned associated machine.

While it is customary in escapement mechanisms to provide alternate operation of each operating rod at a specific point in the operating cycle of the other operating rod, the present invention effects an escapement operation wherein the operating rods 14, 16 are alternately power driven and are solely controlled by the simple expedient of internal porting of the cylinders 30, 32 while at the same time completely eliminating any necessity for mechanical linkage, return springs and the like.

In accordance with the invention, a pair of radially spaced concentric O-rings 68, 70 are seated in a shallow cylindrical chamber 72 jointly formed by cylinder block 22 and cover plate 24 which has an internal recess facing cylinder block 22 in overlying relation to the forward end region of both cylinders 30, 32. The inner O- ring 68 is seated on a circular shoulder 74 provided by an annular extension 76 centrally disposed in chamber 72 to project toward the cylinder block 22. The O-ring 70 is of larger diameter and is seated against the outer peripheral wall 78 of chamber 72. Thus, a first fluid compartment or annulus 80 is provided in chamber 72 between the O-rings 68, 70 which effectively seal oif annulus 80 from fluid communication with a second fluid compartment 82 formed in chamber 72 inwardly of O-ring 68.

By virtue of the above described structure, alternate action of the operating rods 14, 16 is readily achieved whereby one rod is driven and the other rod is power retracted only after the first rod reaches its extended position at the forward limit of its stroke. Only two pairs of passages need be formed in cylinder block 22 for successively effecting alternate reciprocation of each one of the pistons 34, 36 between its extended and retracted positions.

More specifically, a first pair of fluid passages 84, 86 are formed in cylinder block 22 to interconnect cylinders 30, 32 through the annulus 80. Passage 84 extends directly between the extreme forward end of cylinder 32 and the annulus 80. In order that annulus 80 will be in continuous communication with the forward chamber of cylinder 32 irrespective of the position of piston 34, sleeve 40 has a chamfered inner end 88 which provides a small annular forward chamber of triangular cross section when piston 36 is seated against sleeve 40 in its illustrated extended position. Passage 86 communicates the other cylinder 30 with annulus 80 and is shown opening into annulus 80 in diametrically opposed relation to passage 84.

A second pair of passages 90, 92 are formed in cylinder block 22 to interconnect the cylinders 30, 32 through the other fluid compartment 82. Passage 90 opens into cylinder 30 at its extreme forward end defined by sleeve 38 which is chamfered at 94 as described above in connection with sleeve 40. Passage 92 opens into the other cylinder 32 immediately behind piston 44 when it is in its extended position shown in the drawing.

Now assuming that compressed air is being supplied to the rear chamber of cylinder 30 via port 62 and that cylinder 32 is open to atmosphere through port 64, the force of the compressed air will thrust piston 34 forwardly from its illustrated retracted position causing the air to exhaust from the forward chamber of cylinder 30 through passage 90 and fluid compartment 82 and then out passage 92 and into the rear chamber of cylinder 32 to vent to atmosphere through port 64. Since the pressure at ports 92 and 84 are equal during the forward stroke of piston 34, there is no pressure differential across piston 36 and thus no tendency for piston 36 to retract until piston 34 crosses port 86. The frictional forces exerted by the annular seals 48 and 54 maintain piston 36 is position while piston 34 is advanced toward its extended position.

Upon continued forward travel, piston 34 closes off passage 86 and the air remaining in the forward chamber of cylinder 30 exhausts through passage 90 and into the rear chamber of cylinder 32. Passage 86 is formed to open into cylinder 30 immediately behind piston 34 when it is in its extended position, similar to passage 92 as described above in connection with piston 36, and upon bottoming against sleeve 38, piston 34 covers passage 86 to port compressed air directly into the forward chamber of cylinder 32 to overcome atmospheric pressure and the frictional resistance of the seals 48 and 54 to drive piston 36 into its retracted position and to exhaust air behind piston 36 to atmosphere through port 64. The full line supply pressure in the rear chamber of cylinder 30 and in the forward chamber of cylinder 32 maintains pistons 34, 36 in their extended and retracted positions, respectively, whereby the pistons or rods 14, 16 are reversed from that shown in the drawing.

Thereafter, upon reversing the fluid circuit to supply compressed air through port 64 to the rear chamber of cylinder 32 and upon opening cylinder 30 to atmosphere through port 62, rod 14 will be power retracted only after rod 16 is again advanced into its fully extended position. The escapement mechanism will then be conditioned fora repeat cycle.

It will now be seen that the forward chambers of each one of the cylinders 30, 32 are respectively connected with the rear chamber of the other cylinder only when both pistons 34, 36 are bottomed at their forward stroke limits to effect the above described internal porting of the cylinders 30, 32. While the construction is of notable simplicity and incorporates a minimum number of parts, proper escapement operation of the rods 14, 16 is ensured without requiring any interconnecting mechanical linkage, spring members and similar parts commonly associated with conventional mechanism of this type.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

We claim:

1. An article handling mechanism for effecting an escapement operation in feeding a series of articles and comprising a housing having a pair of longitudinally extending passageways, a pair of operating rods projecting outwardly of said housing, said operating rods each having a piston at one end thereof reciprocable in said passageways and dividing their respective passageway into forward and rear chambers, each said piston cooperating with said housing to establish extended and retracted positions at opposite ends of their respective passageway, and fluid operating means including internal fluid passages within said housing for porting the forward chambers of said passageways, said fluid passages including a chamber portion formed in said housing in overlying relation to said passageways, and a pair of radially spaced concentric O-rings seated in said chamber portion and forming first and second isolated fluid compartments therein providing fluid communication between the forward chamber of each one of said passageways and the rear chamber of the other of said passageways only when both said pistons are in their extended positions, said operating rods being controlled solely by said fluid operating means for driving one of said pistons and power retracting the other thereof after said one piston reaches said extended position thereby to alternately actuate said operating rods.

2. An article handling mechanism for effecting an escapement operation in feeding a series of articles and comprising a housing having a pair of longitudinally extending passageways, a pair of operating rods projecting outwardly of said housing, said operating rods each having a piston at one end thereof reciprocable in said passageways and dividing their respective passageway into forward and rear chambers, each said piston cooperating with said housing to establish extended and retracted positions at opposite ends of their respective passageway, and fluid operating means solely controlling said operating rods for driving one of said pistons and power retracting the other thereof after said one piston reaches said extended position thereby to alternately actuate said operating rods, said fluid operating means including internal fluid passages within said housing for porting the forward chambers of said passageways, said fluid passages connecting the forward chamber of each one of said passageways with the rear chamber of the other of said passageways only when both said pistons are in their extended positions, and said internal fluid passages further including a pair of ports in said housing in communication with the rear chambers of said passageways for successively supplying fluid under pressure to each one of the rear chambers in turn and exhausting fluid from the other thereof whereby each said piston is reciprocated between its extended and retracted positions only after the other piston is moved into its extended position.

3. An article handling mechanism for effecting an escapement operation in feeding a series of articles and comprising a housing having a pair of longitudinally extending passageways, a pair of operating rods projecting outwardly of said housing, said operating rods each having a piston at one end thereof reciprocable in said passageways and dividing their respective passageway into forward and rear chambers, each said piston cooperating with said housing to establish extended and retracted positions at opposite ends of their respective passageway, and fluid operating means solely controlling said operating rods for driving one of said pistons and power retracting the other thereof after said one piston reaches said extended position thereby to alternately actuate said operating rods, said fluid operating means including internal fluid passages within said housing for porting the forward chambers of said passageways, said fluid passages including first and second passages formed in said housing and extending between said passageways for connecting the forward chamber of each one of said passageways with the rear chamber of the other of said passageways, said first and second passages each communuicating continuously with the forward chamber of one of said passageways, irrespective of the position of its piston, and opening into the other of said passageways immediately behind its piston when the same is in its extended position thereby to establish fluid flow between said passageways which varies with the position of said pistons.

4. The mechanism of claim 3 wherein said housing includes a cylinder block having said passageways formed therein in side-by-side relation, and a plate secured in face-to-face relation to said cylinder block, said plate having a recess therein facing said cylinder block, said cylinder block together with said plate defining an internal chamber within said housing, and said chamber having first and second isolated fluid compartments formed therein and respectively constituting a part of said first and second passages for establishing fluid communication between said passageways.

5. The mechanism of claim 4 including a pair of radially spaced concentric O-rings seated in said chamber providing said first and second isolated fluid compartments and sealing off said first passage from fluid comrnunication with said second passage.

References Cited UNITED STATES PATENTS 2/1914 Thompson et a1. 91189 7/1964 Oldfield et a1 91189 PAUL E. MASLOUSKY, Primary Examiner. 

